Overview: DATA SHEET CX77140: PA eeModule for CDMA / AMPS (824–849 MHz)
Applications
• Digital cellular (CDMA) • Analog cellular (AMPS) • Wireless local loop (WLL) t 4U . m o c
The CX77140 Power Amplifier Module (PAM) is a dual-mode, fully matched, 10-pin surface mount module developed for Code Division Multiple Access (CDMA) / Advanced Mobile Phone Service (AMPS) cellular handsets and Wireless Local Loop (WLL) applications. This small and efficient power amplifier module packs full coverage of the 824–849 MHz bandwidth into a single pact package. The device meets the stringent IS95 CDMA linearity requirements up to at least 28 dBm output power, and can be driven to levels beyond 31 dBm for high efficiency in FM mode operation. A low current digital pin (VCONT) provides improved efficiency for the low RF power range of operation. The single Gallium Arsenide (GaAs) Microwave Monolithic Integrated Circuit (MMIC) contains all active circuitry in the module. The MMIC contains on-board bias circuitry, as well as input and interstage matching circuits. Output match is realized off-chip and within the module package to optimize efficiency and power performance into a 50 Ω load. This device is manufactured with Skyworks’ GaAs Heterojunction Bipolar Transistor (HBT) process that provides for all positive voltage DC supply operation while maintaining high efficiency and good linearity. Primary bias to the CX77140 is supplied directly from a three-cell Ni-Cd, a single-cell Li-Ion, or other suitable battery with an output in the range of 3.2 to 4.2 volt. Power down is acplished by setting the voltage on the low current reference pin to zero volts. No external supply side switch is needed as typical “off” leakage is a few microamperes with full primary voltage supplied from the battery.
